A number of devices have been utilized in combination with a cover or cap to fully cover a seam that connects adjacent panels. Panel connecting structures such as those disclosed in U.S. patents to Huntington No. 2,855,871, Trostle No. 2,907,287, and Rylander No. 3,063,201 have adjacent sidewalls with a space therebetween but no continuous seam is formed by the edges of the panels. Cotter U.S. Pat. No. 4,001,995 seals abutting flange edges of the panels with a sealant and then snaps a cover over the seam.
The standing seam is in common use to connect panels side by side. This seam is formed by folding the side edge flanges on the outer edges of upright sidewalls of adjacent panels in such a way as to form an integral panel assembly. The novel fastening device of the present invention is used in multiples along a standing seam or similar panel-connecting structure to firmly secure a closure strip such as a batten cap to the seam to fully cover and weatherproof the seam.